Starting Dec. 19, customers can configure and order the cylindrical computer, or purchase one at Apple's own retail stores and those of its authorized resellers.

Prices start at $2,999 for a Mac Pro equipped with a quad-core Intel Xeon E5 processor, 12GB of system memory, dual AMD FirePro graphics processors and 256GB of PCIe-based flash storage. A six-core configuration with 16GB of memory runs $3,999.

Both stock models feature cutting-edge technology, including six Thunderbolt 2 and four USB 3.0 ports, and can drive a trio of 4K displays.

Apple has not revealed at-order upgrade prices for additional memory, a larger SSD (solid-state drive) or other components changes.

Apple introduced the new Mac Pro in June at its annual Worldwide Developers Conference (WWDC) to oos and ahhs from the crowd. Most famously, Philip Schiller, the head of Apple marketing, who after introducing the Mac Pro at the WWDC's opening keynote, pointedly said, "Can't innovate anymore, my ass."

Schiller was referring to criticism by financial and industry analysts that Apple had lost its mojo because it had not released a dramatically-different product since co-founder Steve Jobs' death.

The Mac Pro certainly looks different: Rather than the bulky box of the past -- which resembled 1990s tower-style Windows PCs to the point of being indistinguishable from some -- the newest is a 10-in. black cylinder about 7 in. in diameter that weighs just 11 pounds.

Apple last gave the Mac Pro a facelift in 2010, then tweaked the hardware in June 2012 with a minor refresh. The long stretch between iterations led to speculation that Apple was planning to kill the Mac Pro, or fold it into a higher-end iMac configuration.

The guts of the Mac Pro are squeezed into a 9x6-in. black aluminum cylinder, a feat that Apple's head of marketing called "truly revolutionary, truly radical." (Image: Apple.)

The Mac Pro may be a flagship of sorts for Apple, which has a history of catering to designers, developers, engineers and other creative professionals with its upper-tier hardware, but the computer sells in very small numbers compared to the more prosaic iMac desktop and MacBook notebook lines.

In fact, Apple -- which abandoned the word "Computer" in its official name in early 2007 -- is only incidentally a personal computer maker: In the third quarter, the one most recently reported, Mac revenue was $5.6 billion, or just 15% of the period's total.

At this point, Apple is primarily a smartphone company. In the same quarter, iPhone revenue topped $19.5 billion, accounting for 52% of the total for the three months.